I did a search and couldn't find a discussion that quite covered my experience with mono vs stereo piano sound through a PA system so I thought I would share my own experience.
After many years playing my Yamaha P200 and CP33 through headphones or stereo monitors I recently started playing in public for the first time and had to get to grips with amplification i.e. buy a PA system. I dived in and bought a Bose L1 Compact and was immediately very disappointed with the quality of the piano sounds. I had got used to the great Yamaha piano sounds and by comparision, the Bose sounded terrible - only with piano patches - other instrument patches sounded fine. I use Band in A Box on a laptop and a small mixer and tried every possible combination of connections but no matter what I did (including using the L/mono keyboard out connection) the piano always sounded "thin" and "reedy" through the single Bose PA.
I then did a lot of research, especially on the Bose forum, and discovered this "stereo summed to mono" issue is well known but perhaps not very well understood. It seems that piano patches are different from every other instrument because they are produced with left and right samples that cover the width of the accoustic piano. The only way to maintain this piano realism is to keep the channels separate until they enter your ear. If you sum to mono the samples intefer with each other i.e. you get phase cancellation and the piano realism is lost. This happens regardless of the point at which the channels are summed - from the keyboard, to the mixer, to the PA.
I was convinced enough to go out and buy a second Bose Compact (yes, I know, another $1000) and connected them in stereo and what a difference! My beloved Yamaha piano sound was back. This was very obvious to me and just about everywhere in a room where I was playing for about 130 people. Standing far to the left or right the improvement wasn't as obvious as you might expect but if I placed the two Compacts right next to each other there was still a big improvement.
I have heard it said that stereo is a waste of time when gigging because only a few people sitting in the sweet spot can hear the stereo. I had no answer to this until I realized that the issue is all about phase cancellation, not about listening in stereo. If you sum a piano sound to mono you degrade the quality regardless of where people are sitting. The improvement was dramatic with my Bose PAs which claim to have a "spatial" sound field but cannor say how things would sound using stereo through more conventional speakers - perhaps someone can comment?
The bottom line is that I play better when I sound better.
Regards
Tony
After many years playing my Yamaha P200 and CP33 through headphones or stereo monitors I recently started playing in public for the first time and had to get to grips with amplification i.e. buy a PA system. I dived in and bought a Bose L1 Compact and was immediately very disappointed with the quality of the piano sounds. I had got used to the great Yamaha piano sounds and by comparision, the Bose sounded terrible - only with piano patches - other instrument patches sounded fine. I use Band in A Box on a laptop and a small mixer and tried every possible combination of connections but no matter what I did (including using the L/mono keyboard out connection) the piano always sounded "thin" and "reedy" through the single Bose PA.
I then did a lot of research, especially on the Bose forum, and discovered this "stereo summed to mono" issue is well known but perhaps not very well understood. It seems that piano patches are different from every other instrument because they are produced with left and right samples that cover the width of the accoustic piano. The only way to maintain this piano realism is to keep the channels separate until they enter your ear. If you sum to mono the samples intefer with each other i.e. you get phase cancellation and the piano realism is lost. This happens regardless of the point at which the channels are summed - from the keyboard, to the mixer, to the PA.
I was convinced enough to go out and buy a second Bose Compact (yes, I know, another $1000) and connected them in stereo and what a difference! My beloved Yamaha piano sound was back. This was very obvious to me and just about everywhere in a room where I was playing for about 130 people. Standing far to the left or right the improvement wasn't as obvious as you might expect but if I placed the two Compacts right next to each other there was still a big improvement.
I have heard it said that stereo is a waste of time when gigging because only a few people sitting in the sweet spot can hear the stereo. I had no answer to this until I realized that the issue is all about phase cancellation, not about listening in stereo. If you sum a piano sound to mono you degrade the quality regardless of where people are sitting. The improvement was dramatic with my Bose PAs which claim to have a "spatial" sound field but cannor say how things would sound using stereo through more conventional speakers - perhaps someone can comment?
The bottom line is that I play better when I sound better.
Regards
Tony
